1. Field
Embodiments discussed herein relate to a method of making monolithic Zirconium Carbide (ZrC).
2. Description of the Related Art
Zirconium Carbide (ZrC) is a ceramic that is used as tool bits, as a coating layer for nuclear fuel, and in ultra-high temperature (e.g., 3500° C.) applications. The ceramic is also corrosion and water resistant. High density (i.e., greater than 90% of a theoretical density of the ZrC) and small grain sizes (i.e., 1 to 12 μm) are desirable traits for ZrC because these traits lead to good material hardness and mechanical strength. ZrC should have low levels of impurities and a stoichiometric ratio that is approximately ZrC1.0.
Related methods for making monolithic discs of ZrC include “sintering” and “hot press”, but these methods have limitations. For the hot press method to produce ZrC with 90% density, very high temperatures, i.e., 2200 to 2700° C., are required. Even when high temperatures are used, the produced ZrC has a relatively large grain size (16 to 120 μm). Sintering also requires high temperatures (2200 to 2700° C.) to create monolithic discs. The result is a monolithic disc of ZrC with relatively large grain size (20 to 65 μm) and low density (70 to 90%).
Both processes produce monolithic discs of ZrC with large grain sizes. Large grain sizes correspond to reduced material hardness and mechanical strength. Both processes require relatively high energy to meet the high temperature requirements.
In light of the foregoing, there is a need for a method of making monolithic ZrC having high density (i.e. above 90%) and small grain sizes (1 to 12 μm).